Container, produced from a spiral-shaped, bent sheet strip

ABSTRACT

The invention relates to a container ( 10 ) produced from a spiral-shaped, bent sheet strip ( 20 ), wherein the sheet strip ( 20 ) has a first edge section ( 22 ) extending in a spiral shape, which is bent, forming a bending edge ( 24 ) extending in a spiral shape, toward the inside or the outside of the container ( 10 ), and wherein the sheet strip ( 20 ) has a second edge section ( 32 ) which is opposite the first edge section ( 22 ) in relation to the longitudinal direction of the sheet strip ( 20 ) and likewise extends in a spiral shape, characterized in that the second edge section ( 32 ) of the sheet strip ( 20 ) overlaps a third section ( 28 ) of the sheet strip ( 20 ), which is opposite the first edge section ( 22 ) in relation to the bending edge ( 24 ) and is adjacent to the bending edge ( 24 ), in that the second edge section ( 32 ) and the third section ( 28 ) of the sheet strip ( 20 ) are welded to each other in the region of the overlap ( 30 ), and in that the welding seam ( 40 ) extends at least partially into the region between the second edge section ( 32 ) and the third section ( 28 ) of the sheet strip ( 20 ).

The invention relates to a container produced from a spiral-shaped,curved sheet strip, which may be used, for example, as storage containerfor liquid or solid agricultural produce or waste, or as biogas reactor.

The production of containers of this kind is known from DE 2 250 239 A.In this method, a sheet strip is used to form a spiral with a diameterthat corresponds to that of the container diameter. The associated,spiral-shaped sheet strip edges are folded out and then connected toeach other on the outside of the container by means of a seam. Thismanufacturing method, known as the LIPP double-seam system, provides fora quick and simple manufacture of containers of different diameters anddifferent heights. By using mobile sheet folding and assembly facilitiesthe container may be manufactured directly at the desired erection site.

From the document DE 199 39 180 A1 a container made from aspiral-shaped, curved sheet strip is known, in which a first edgesection is folded towards the outside, thus forming a spiral-shapedfold-out edge. The second edge section of the sheet strip is also foldedto the outside and connected to the first edge section by an outsideseam. In the vicinity of the butt joint of the folded edge sections thesheet strip is welded on the inside of the container for sealingpurposes.

For common applications such as, for example, the storage of bulkmaterial from the agricultural or forestry sectors, or of bio waste, themanufactured containers seal very well, are structurally stable and aremedia resistant. Further applications such as, for example, the storageof plant-based oils, require a greater container volume and thus asignificantly increased mechanical rigidity of the containers to beeconomically viable, which can so far only be achieved withmanufacturing methods that involve a significantly greater investment interms of time and cost.

The invention is based on the object of providing a container that isproduced from a spiral-shaped sheet strip, which further increases theapplication spectrum of containers of this kind, in particular a largestorage volume and/or an increased mechanical rigidity, but that isstill simple and quick to produce.

The object is met by the container as specified in claim 1. Particularembodiments of the invention are specified in the sub-claims.

In one embodiment of the invention the container is produced from aspiral-shaped, curved sheet strip, wherein the sheet strip comprises afirst spiral-shaped edge section that is folded to the inside or to theoutside of the container and thus forms a spiral-shaped fold-out edge,and in which the sheet strip features a second edge section which, withregard to the longitudinal direction of the sheet strip, is disposedopposite the first edge section and which also extends spiral-shaped.The second edge section of the sheet strip overlaps a third section ofthe sheet strip which, with regard to the fold-out edge, is disposedopposite the first edge section and adjoins the fold-out edge. Thesecond edge section and the third section of the sheet strip are weldedtogether in the vicinity of the overlap, where the welding seam extendsat least partially into the area between the second edge section and thethird section of the sheet strip.

As a result of the spread of the welding seam up to at least the edgeregion of the overlap between the second edge section and the thirdsection, where said edge region adjoins the fold-out edge, abreak-proof, mechanical connection of the sheet strip edges is achieved,which provides sufficient mechanical rigidity even in large-volumecontainers for the storage of liquid media. The welding seam is in thisinstance located preferably in the region of the fold-out edge, and thefold-out edge may in particular be partially or even fully covered bythe welding seam. The overlap of the third section by the second edgesection is preferably a multiple of the thickness of the sheet strip, inparticular more than two times and preferably more than three times thesheet thickness. The overlapping of the third section by the second edgesection is in vertical direction. The first edge section and the secondedge section each show the longitudinal edge of the sheet strip.

In one embodiment the height of the welding seam is more than 100%, inparticular more than 120% and preferably more than 150% of the thicknessof the sheet strip, in particular the thickness of the sheet strip inthe vicinity of the fold-out edge. The sheet strip has preferably aconstant thickness over its entire extension in longitudinal andtransverse direction. The height of the welding seam ensures that thewelding seam does not constitute a bottleneck for the flow of force sothat it is made certain that the effective forces that extend from thethird section via the welding seam into the second edge section arereliably transferred without the occurrence of force peaks and thusstress peaks in the vicinity of the welding seam.

In one embodiment the height of that part of the welding seam thatextends in the vicinity between the edge section and the third sectionof the sheet strip is more than 20%, in particular more than 25% andpreferably more than 30% of the thickness of the sheet strip, inparticular of the thickness of the sheet strip in the vicinity of thewelding seam. This causes the forces to be transferred via the weldingseam also into that area of the sheet strip, in particular into thatarea of the third section of the sheet strip which remained mechanicallyessentially without load due to being folded out and the formation ofthe fold-out edge. This leads to a significantly increased rigidity ofthe welding connection.

In one embodiment welding is performed at least partially also in thevicinity of the fold-out edge; for example, the fold-out edge may becovered partially or even fully by the welding seam. This furtherincreases the mechanical rigidity of the welding seam since inparticular the areas of the sheet strip that are close to the surfacethat have been stressed through folding out, are melted by the weldingprocess in the vicinity of the fold-out edge and become a part of thewelding seam after solidifying.

In one embodiment the welding seam extends into that area in which thesecond edge section and the third section extend parallel to each other.The second edge section and the third section of the sheet strip may, inthe vicinity of the overlap, extend parallel and in particularconcentric to each other in the direction of the circumference, and mayhave a constant distance to each other or they may be in contact witheach other already. Both have a favorable effect on the rigidity of thewelding connection.

In one embodiment the second edge section overlaps the third section ofthe sheet strip on the inside of the container. In this instance thefirst edge section may be folded outwards so that the fold-out edge isaccessible from the outside and the welding process in particular cantake place from the outside of the container to be manufactured. Thissignificantly simplifies the manufacturing process, in particularbecause the welding device does not have to be moved from the inside ofthe container to the outside after completion of the manufacturingprocess.

In one embodiment the second edge section is welded with itsspiral-shaped end edge to the third section of the sheet strip. Thiswelding connection may be implemented as an alternative to or inaddition to the welding connection in the vicinity of the fold-out edge.Provided that the second edge section overlaps the third section on theinside of the container, the container is also fluid-tight on the insideand the occurrence of germ pockets is reliably prevented, which isparticularly important for the storage of foodstuffs.

In one embodiment an end edge of the second edge section formspreferably on the inside of the container a step that extends oblique ortransverse to the vertical longitudinal axis of the container. Thissimplifies the welding process because the welding seam can be formedreliably at the butt joint of the two sheet sections at the area of thestep that extends oblique or transverse in particular.

In one embodiment the fold-out edge is formed by the first edge sectionthat is folded towards the outside of the container, where said firstedge section is disposed above the opposite second edge section inrelation to the longitudinal direction of the sheet strip. The fold-outis performed essentially at right angles, and the length of the foldedout section is in one embodiment more than two times, in particular morethan three times and preferably more than five times the thickness ofthe sheet strip. This increases the mechanical rigidity of thecontainer. As a result of the sill-like, radially outward protruding,first edge section it is, moreover, possible to apply the externallylocated welding seam in a very simple manner; in particular, the weldingplant may be guided at an acute angle of preferably more than 20° andless than 70° with respect to the horizontal at the butt joint of thesecond edge section and the fold-out edge, which permits the simpleproduction of a sufficiently deep welding seam and thus a sufficientlyrigid welding connection.

In one embodiment the third section of the sheet strip, which adjoinsthe fold-out edge in the direction of the second edge section, is foldedout as an offset with respect to a fourth section of the sheet strip,which adjoins the offset in the direction of the second edge section,and is in particular folded towards the outside of the container. Thisallows the matching edge sections of the sheet strip to be laidalongside each other without, or with only reduced, mechanical tension.If the offset is of sufficient size, a self-adjustment of the matchingedges of the sheet strips to each other occurs; in particular the secondedge section is able to brace itself on the offset disposed between thethird section and the fourth section, which on the one hand furthersimplifies the manufacturing process and increases the rigidity and onthe other hand ensures an accurately fitting connection.

In one embodiment the radial displacement of the second edge sectioncompared to the fourth section of the sheet strip, caused by the offset,is less than 95% of the thickness of the sheet strip, in particular lessthan 90% and preferably less than 85%. This causes the two matching edgesections to be slightly elastically deformed during manufacture, andthrough that they lay alongside each other in a pre-stressed state. Thisleads to a further stiffening of the container.

In one embodiment the second edge section is, through a further offset,folded preferably into the inside of the container with respect to afifth section, which continues on from the offset in the direction ofthe first edge section. This offset may be disposed in the vicinity ofthe radially outside located fold-out edge of the first edge section.The radial displacement of the second edge section with respect to thefifth section, caused by the offset, may be less than 95% of the sheetstrip thickness, in particular less than 90% and preferably less than85%.

In one embodiment the container is surrounded by a stabilizing device,which extends upwards from the support surface of the container, andwhich is at least sectionally and/or at discrete positions positivelyconnected to the container, in particular positively connected in radialdirection so as to at least partially absorb the forces acting upon thecontainer. In this instance the stabilizing device may extend to atleast part of the height of the container, in particular more than 20%and preferably more than 30%. The positive connections may be made atdiscrete locations around the circumference and/or in verticaldirection, for example through welding the radially outwards folded,first edge section to the stabilizing device. The stabilizing device maybe formed, for example, through several stabilizing elements, forexample U-shaped elements or elements of triangular shape in lateralelevation, which are erected preferably equidistant around thecircumference of the container, anchored in the foundation and extendingvertically.

In one embodiment the stabilizing device is formed by an outercontainer, and the annular space in between the container and the outercontainer may at least sectionally and/or at least partially be filledwith a material that provides a positive connection between thecontainer and the outer container. For example, the space in between maybe filled with concrete. In this instance the container and the outercontainer may be disposed concentrically on a foundation slab of thecontainer.

Further advantages, characteristics and details of the invention becomeapparent from the sub-claims as well as from the following description,in which several exemplary embodiments are described in detail withreference to the drawing. The characteristics mentioned in the claimsand in the description may be essential to the invention, individuallyor in any combination.

FIG. 1 shows a side elevation of the container according to theinvention,

FIG. 2 shows a partial plan view of the container in FIG. 1,

FIG. 3 shows enlarged a section of the side wall of the container inFIG. 1,

FIG. 4 shows enlarged a section through the connection point IV of afirst exemplary embodiment of the container in FIG. 1,

FIG. 5 shows a further exemplary embodiment of the invention in theenlarged section of the connection point IV,

FIG. 6 shows a side elevation of a third exemplary embodiment of theinvention,

FIG. 7 shows the respective plan view in sections,

FIG. 8 shows enlarged a section of the side wall of the container inFIG. 6,

FIG. 9 shows a section through a stabilizing element,

FIG. 10 shows a side elevation of a fourth exemplary embodiment of theinvention,

FIG. 11 shows the respective plan view in sections,

FIG. 12 shows enlarged a section of a fifth exemplary embodiment, and

FIG. 13 shows enlarged a section of a sixth exemplary embodiment.

FIG. 1 depicts a side elevation of a container 10 according to theinvention that may be used for the storage of bulk material in theagricultural and forestry sectors, for example, grains, woodchips or biowaste as well as for the storage of water, waste water, sewage sludge,liquid energy carriers and also for the storage of gas. FIG. 2 is apartial plan view of the container in FIG. 1.

The container 10 is on its outside and its inside essentiallycylindrical, in particular circular-cylindrical, with a verticallyextending, longitudinal axis 12. The container 10 rests on a foundation1 that may, for example, be a concrete slab, and which, like the basearea of the container 10 in plan view, may be circular or, as shown inthe exemplary embodiment, may be a polygon. The cylindrical section ofcontainer 10 is covered at the top by a conical or a truncatedcone-shaped roof 2.

The container 10 is manufactured by using a spiral-shaped, curved sheetstrip 20, preferably directly at the erection site of the container 10.The diameter 14 of the container 10 may, for example, be between 4 m and20 m or more. The height 16 of the container 10 may be between 2 m and20 m or more. The filling capacity of the container 10 may, for example,be between 15 m³ and 8000 m³. The preferably homogenous thickness 26(FIG. 4) of the sheet strip 20 is between 2 mm and 14 mm, and may in thepresent instance be in particular more than 5 mm, preferably more than 6mm and less than 12 mm, for example between 8 mm and 10 mm. The width 18of the sheet strip 20 may be between 20 cm and 100 cm, in particularbetween 30 cm and 80 cm and preferably between 40 cm and 60 cm; in theexemplary embodiment shown, the width 18 of the sheet strip 20 isapproximately 50 cm.

FIG. 3 depicts in an enlarged representation a section of the side wallof the container 10 in FIG. 1, and the FIG. 4 depicts in an enlargedrepresentation a section through the connection point IV of a firstexemplary embodiment of the container 10 in FIG. 1. The sheet strip 20features a first edge section 22 that forms the upper longitudinal edgeof the sheet strip 20, which is folded out to the outside of thecontainer 10 by forming a spiral-shaped fold-out edge 24. The radialextension of the folded-out, first edge section 22 is more than fivetimes and less than ten times, in the exemplary embodiment approximatelyseven times the thickness 26 of the sheet strip 20.

A third section 28 of the sheet strip 20 which, in relation to thefold-out edge 24, is disposed opposite the first edge section 22 andadjoins the fold-out edge 24, is overlapped on the inside of thecontainer 10 by a second edge section 32 of the sheet strip 20, where inthe area of the overlap 30 the second edge section 32 and the thirdsection 28 extend essentially parallel to each other and also extend ina curved manner particularly concentrically in relation to thelongitudinal axis 12, and may have a constant distance from each otheror may even lay alongside each other. The overlap 30 extends in verticaldirection by more than two times, in particular more than three timesand preferably more than five times, in the exemplary embodimentapproximately seven times, the thickness 26 of the sheet strip 20. Theoverlap 30 may in particular be more than 50% and less than 200% of theradial extension of the folded-out, first edge section 22, in particularmore than 80% and less than 125% and preferably more than 90% and lessthan 110%.

The third section 28 is shifted in particular radially to the outside byan offset 34 with respect to a fourth section 36 of the sheet strip 20that adjoins the offset 34 in the direction towards the second edgesection 32. In this instance the internal diameter of the container 10is essentially the same in the vicinity of the fourth section 36 as inthe vicinity of the second edge section 32, so that the second edgesection 32 is able to rest on the inside of container 10 against theoffset 34, or that the second edge section 32 and the fourth section 36are at least flush on the inside of the container 10. The radialdisplacement of the third section 28 radially outwards compared to thefourth section 36 may correspond essentially to that of the thickness 26of the sheet strip 20, or may even be slightly smaller, so that thethird section 28 is retained alongside the second edge section 32 inparticular by an elastic deformation of the sheet strip 20 in thevicinity of the offset 34.

On the outside of the container 10, in the vicinity of the fold-out edge24, a welding seam 40 is provided to connect the second edge section 32to the adjoining section of the sheet strip 20, in particular in thevicinity of the fold-out edge 24. In this instance the welding seam 40extends at least partially into the area between the second edge section32 and the third section 28. The height 42 of the welding seam 40 in theexemplary embodiment is more than 250% of the thickness 26 of the sheetstrip 20 in the vicinity of the fold-out edge 24 and thus provides areliable, stable flow of force between the edge sections of the sheetstrip 20 that adjoin each other in vertical direction, and gives thecontainer 10 therefore a particularly high level of rigidity. The width44 of the welding seam in the exemplary embodiment is more than 150% ofthe thickness 26 of the sheet strip 20, which also contributes to theincrease in rigidity of the welding connection and thus to that ofcontainer 10.

The FIG. 5 depicts a second exemplary embodiment of the invention in theenlarged section of the connection point IV, where the difference to thefirst exemplary embodiment is essentially that on the inside of thecontainer 10 the sheet strip 20 is covered, and in particular laminated,with a thin lining 38, shown in the exemplary embodiment as a thin layerof stainless steel. This provides the container with an increasedresistance towards any filling material and is, for example, alsosuitable for drinking water or other foodstuffs.

The height 46 of the first part of the welding seam 40, which extends inthe area between the second edge section 32 and the third section 28 ofthe sheet strip 20, is in the exemplary embodiment more than thethickness 26 of the sheet strip 20. Even the second part 48 of thewelding seam 40, which extends into the area between the second edgesection 32 and the third section 28 that adjoins the fold-out edge 24,shows in the exemplary embodiment a thickness that is more than 30% ofthe thickness 26 of the sheet strip 20. If necessary, the welding seam40 may extend even further into the area between the second edge section32 and the third section 28 for the purpose of further increasing themechanical strength of the welding connection and thus that of thecontainer 10. Through the second part 48 of the height of the weldingseam 40, which extends in that area where the second edge section 32 andthe third section 28 extend parallel to each other, the connection ismade also in a section of the sheet strip 20 that was not stressed, ornot significantly stressed, through the folding out of the first edgesection 22, which increases the mechanical strength of the connection.

The FIG. 6 depicts a side elevation of a third exemplary embodiment ofthe invention in which the container 10 may be constructed as describedbefore, but is in addition surrounded by a stabilizing device 50, whichextends from the foundation 1 upwards and which, in the exemplaryembodiment shown, is positively connected at discrete locations aroundthe circumference of the container 10 so as to at least partially absorbthe forces that act upon container 10. The FIG. 7 shows in part therespective plan view. The stabilizing device 50 comprises a total ofeight stabilizing elements 52 that are arranged equidistantly around thecircumference of the container up to a height of approximately 50% ofthe container, each of which is connected to the outside of thecontainer 10 punctiformly or linearly. The stabilizing elements 52 aresufficiently anchored in the foundation 1.

The FIG. 8 depicts enlarged a section of the side wall of the container10 in FIG. 6, and the FIG. 9 shows a section through a stabilizingelement 52 that is U-shaped in cross-section. The exemplary embodimentshows the stabilizing element 52 as a U-shaped iron profile to which theradially outer-most end of the first edge section 22 is attached bymeans of a further welding seam 54. The radial distance between the wallof the container 10 and the stabilizing element 52 may be less thanfifteen times, in particular less than twelve times and preferably lessthan ten times the thickness of the sheet strip 20. Due to the radialorientation of the folded-out, first edge section 22, a high level ofmechanical strength of the connection between the container 10 and thestabilizing element 52 is achieved, even at the comparatively largedistances. The U-shape of the stabilizing elements 52 results in a highbending resistance with respect to forces that occur radially inrelation to the longitudinal axis 12 of the container 10.

FIG. 10 depicts a side elevation of a fourth exemplary embodiment of theinvention and the FIG. 11 shows the corresponding partial plan view.Whilst the container 10 is constructed as described above, thestabilizing device 150 is now provided in form of an outer container,which surrounds the container 10 in the bottom section preferablyconcentrically in relation to the longitudinal axis 12. The exemplaryembodiment shows that the stabilizing device 150 is constructed similarto or identical with the container 10 from a spiral-shaped, curved sheetstrip 120, in which in particular the welding connection for the outercontainer of the stabilizing device 150 can be made in the same manneras described for the container 20. The positive connection between thecontainer 10 and the stabilizing device 150 may be achieved in that thespace 56 between the inner container 10, or its sheet strip 20respectively, and the outer stabilizing device 150, or its sheet strip120 respectively, is filled with a material 60 such as, for example,concrete.

The FIG. 12 shows enlarged a section of a fifth exemplary embodiment ofthe invention in the area of the space 56 between the container 10 andthe stabilizing device 150. In contrast to the exemplary embodimentsdescribed so far, the folded-out first edge section 122 in the container110 is formed by the, in vertical direction, lower longitudinal edge ofthe sheet strip 20, and the second edge section 132 is folded radiallyto the inside by way of an offset 134. The connection between the secondedge section 132 and the third section 128 is achieved through a weldingseam 140 that is placed onto the end edge of the second end section 132.The end edge of the second end section 132 may form a step on the insideof the container 110 that forms an angle 58 to the vertical that is lessthan 90° and in particular approximately 70° as shown in the exemplaryembodiment. This allows the welding seam 140 to be placed securely inthe transition section from the second edge section 132 to the thirdsection 128, and in particular due to the gravitational force thewelding seam drops into the gap between the two sections of the sheetstrip 20. Regarding its height and width the welding seam 140 mayotherwise be formed as described above for the welding seam 40.

The stabilizing device 150, made from the spiral-shaped, curved sheetstrip 120, may be made in the same manner as described in relation withcontainer 10, in particular concerning the arrangement and formation ofthe welding seam 141, which may be formed in the same way as the abovedescribed welding seam 40 of container 10. The space 56 between thecontainer 110 and the stabilizing device 150 is filled with concrete asa positive connecting material 60; in particular, by using the container110 and the stabilizing device 150 as formwork, the material 60 may befilled into the space 56.

The FIG. 13 shows enlarged a section through a sixth exemplaryembodiment of the invention where, in contrast to the exemplaryembodiment of FIG. 12, the container 10 is formed as described inconnection with FIG. 5. The container 10 comprises therefore on itsinside a lining 38 made, for example, from stainless steel. The weldingconnection for container 10 and for the stabilizing device 150 is maderadially outside through the welding seams 40 and 141 respectively. As aresult of the material 60 in the space between the container 10 and thestabilizing device 150, the welding seam 40 of container 10 is providedwith further mechanical stabilization.

1. Container (10), produced from a spiral-shaped, curved sheet strip(20), wherein the sheet strip (20) comprises a first spiral-shaped edgesection (22) that is folded to the inside or to the outside of thecontainer (10) and thus forms a spiral-shaped fold-out edge (24), and inwhich the sheet strip (20) comprises a second edge section (32) which,with regard to the longitudinal direction of the sheet strip (20), isdisposed opposite the first edge section (22) and which also extendsspiral-shaped, characterized in that the second edge section (32) of thesheet strip (20) overlaps a third section (28) of the sheet strip (20)which, with regard to the fold-out edge (24), is disposed opposite thefirst edge section (22) and adjoins the fold-out edge (24), that thesecond edge section (32) and the third section (28) of the sheet strip(20) are welded together in the vicinity of the overlap (30), and thatthe welding seam (40) extends at least partially into the area betweenthe second edge section (32) and the third section (28) of the sheetstrip (20).
 2. Container (10) according to claim 1, characterized inthat the height (42) of the welding seam (40) is more than 100%, inparticular more than 120% and preferably more than 150% of the thicknessof the sheet strip (20).
 3. Container (10) according to claim 1,characterized in that the height (46) of that part of the welding seam(40), which extends in the area between the second edge section (32) andthe third section (28) of the sheet strip (20), is more than 20%, inparticular more than 25% and preferably more than 30% of the thickness(26) of the sheet strip (20).
 4. Container (10) according to claim 1,characterized in that the welding seam (40) extends into that area inwhich the second edge section (32) and the third section (28) extendparallel to each other.
 5. Container (10) according to claim 1,characterized in that the second edge section (32) overlaps the thirdsection (28) of the sheet strip (20) on the inside of the container(10).
 6. Container (10) according to claim 1, characterized in that thewelding seam (40) is disposed on the outside of the container (10). 7.Container (10) according to claim 1, characterized in that the secondedge section (32) is welded at its spiral-shaped end edge to the thirdsection (28) of the sheet strip (20).
 8. Container (10) according toclaim 1, characterized in that an end edge of the second edge section(32) forms on the inside of the container (10) an obliquely, inparticular transverse to the vertical longitudinal axis (12) of thecontainer (10), extending step.
 9. Container (10) according to claim 1,characterized in that the container (10) is surrounded by a stabilizingdevice (50), which extends upwards starting from the support surface ofthe container (10), and which is at least in sections and/or in discretepositions positively connected to the container (10), thus absorbing atleast partially the forces that are acting on the container (10). 10.Container (10) according to claim 9, characterized in that thestabilizing device (50) is formed by an outer container, and that theannular space (56) between the container (10) and the outer container isfilled at least in sections and/or at least partially with a material(60) that provides a positive connection between the container (10) andthe outer container.
 11. Container (10) according to claim 10,characterized in that the outer container is made from a spiral-shaped,curved sheet strip (120).